Open Access. Powered by Scholars. Published by Universities.®
- Publication
Articles 1 - 5 of 5
Full-Text Articles in Physics
Rapid Colloidal Solidifications Under Local Nonequilibrium Diffusion Conditions, Sergey Sobolev
Rapid Colloidal Solidifications Under Local Nonequilibrium Diffusion Conditions, Sergey Sobolev
Sergey Sobolev
Partition coefficient for rapid solidification of colloidal suspensions has been calculated under local nonequilibrium diffusion conditions typically used when processing advanced materials. It has been demonstrated that the local nonequilibrium diffusion effects stabilize the planar solid liquid interface and lead to an abrupt transition to diffusionless solidification with complete particle trapping. The effective diffusion coefficient, which depends on interface velocity and particle size, has been introduced. It explains the strong dependences of the partition coefficient and the velocity leading to absolute stability of a planar solid–liquid interface on particle size.
An Analytical Model For Complete Solute Trapping During Rapid Solidification Of Binary Alloys, Sergey Sobolev
An Analytical Model For Complete Solute Trapping During Rapid Solidification Of Binary Alloys, Sergey Sobolev
Sergey Sobolev
An analytical model has been developed to describe solute partitioning during rapid solidification of binary alloys under local nonequilibrium conditions. The model takes into account the deviations from equilibrium both at the solid–liquid interface according to the kinetic approach of Jackson et al. based on Monte Carlo simulations and in the bulk liquid using local nonequilibrium diffusion model (LNDM). The dimensionless growth parameter b found in the Monte Carlo simulations as the important parameter for solute trapping has been modified for the local nonequilibrium diffusion case. An analytical expression has been developed for the velocity-dependent partition coefficient K which predicts …
Segregation Of Bismuth To Triple Junctions In Copper, K.-M. Yin, Alexander H. King, T.E. Hsieh, F.-R. Chen, J.J. Kai, L. Chang
Segregation Of Bismuth To Triple Junctions In Copper, K.-M. Yin, Alexander H. King, T.E. Hsieh, F.-R. Chen, J.J. Kai, L. Chang
Alexander H. King
Bismuth segregation in copper has been studied using energy-dispersive X-ray spectrometry (EDX) in a JEOL 2010F transmission electron microscope. In addition to the expected solute enrichment at grain boundaries, we have observed extremely high concentrations of bismuth at certain triple junctions, with significantly greater enrichment factors than in the adjacent grain boundaries. It is shown here that the triple junction segregation is a function of the parameters of the grain boundaries at the triple line, and existence of this type of segregation implies that the affected triple junctions embody excess free energy. At least one of the observed triple junctions …
Effects Of Local Non-Equilibrium Solute Diffusion On Rapid Solidification Of Alloys, Sergey Sobolev
Effects Of Local Non-Equilibrium Solute Diffusion On Rapid Solidification Of Alloys, Sergey Sobolev
Sergey Sobolev
A conceptual foundation for the study of local non-equilibrium solute diffusion under rapid solidifica- tion conditions is proposed. The model takes into account the relaxation to local equilibrium of the solute flux and incorporates two diffusion speeds, VDb, the bulk liquid diffusion speed, and VDi, the interface diffusive speed, as the most important parameters governing the solute concentration in the liquid phase and solute partitioning. The analysis of the model predicts complete solute trapping and the transition to a purely thermally controlled solidification, which occur abruptly when the interface velocity V equals the bulk liquid diffusion speed VDb. The abrupt …
Local Non-Equilibrium Model For Rapid Solidification Of Undercooled Melts, Sergey Sobolev
Local Non-Equilibrium Model For Rapid Solidification Of Undercooled Melts, Sergey Sobolev
Sergey Sobolev
No abstract provided.